Let's not kid ourselves first and foremost, some English dubs are really not that swell. I've seen them, I've been in them, and I'm pretty positive I've been a contributing factor to at least one of them. The problem is that for many audiences, the performance quality starts and ends with the voice actor themselves. Granted, this is true to an extent; no amount of sound engineering magic can save a terrible performance. But there's numerous people the voice actor also has to play ball with and satisfy:
The parent company, who may already have a specific vision in mind for the character (You wanted seductive swagger? Too bad, we think lecherous pervert is funnier!)
The localization director, who may prefer one style of performance over another (Do they like exaggerated emotions? Do they want Mass Effect-level realism? Do they actually have no idea what they're doing? All 3 types exist!) The casting director, who may want you to not sound like X because they already recorded someone else who sounds close to X, and now that would just make it weird so you have to sound like Y instead.
And many others.
Another core fact many people forget is that just like Western Animation projects done here, many anime projects in Japan are also recorded as "pre-lay" - that is, the voiceover is done FIRST and the animators work around it, rather than the reverse. This means that the original Japanese VO has a lot more freedom in terms of performance and pacing, whereas the company that DUBS it has to stick to the pre-existing lip flaps and timing that the original actors got to set.So already, you're dealing with a difference in situations where the Japanese VA got to play with a line to pretty much their heart's desire, whereas the English VA has to keep within a set of guidelines. Anime is usually the most notorious with this whereas videogames are more relaxed, but there were LOTS of cases in Trails of Cold Steel (such as battle lines) where I had to exactly match the timing of the Japanese VO within a few frames of a second.
Finally, Japanese is a very content-focused language, whereas English is very context-driven. A person using Japanese will make a very careful distinction between using the word "friend" and the word "partner", because their use signifies a very particular meaning to the message as a whole. In contrast, the meaning behind the word "friend" can change significantly for me depending on how the person says it; one small change in tone can take it from genuine appreciation, to scathing sarcasm. Sometimes these differences also affect the actual pacing or emphasis of certain words...which may not be possible when you're trying to stick to a pre-established timestamp.
I can already name one role that I, personally, love with the bottom of my heart...but I heavily dislike how the finished product came out because the combination of Client Wishes, Lip-Sync Limitation, and Word of God demanded a much different performance than what I had in mind. The client was super happy, but I don't know if the fans will be - and at the end of the day, the client is the one who cuts my checks. I do not expect my performances/career to magically turn people to dubs over subs, and I especially am not going to condemn people for preferring one over the other. What I do ask, at the very least, is that you support the companies who make games you enjoy & want to see more of, however you choose to (legally) do it, and consider taking some time to let the people who entertained you know that they were entertained. Very few of us like the popularity contest that studios are employing right now where being Socially Influential makes you more likely to get big parts, but the fact remains that Fan Demand still does have a very real impact; if you like us, they'll like us, and we'll probably get to work more.
I got into this career because I love performing and living through all these different worlds and events, but I also continue to enjoy it because of the incredible fandoms that build up around them and the people who share their passions for things the same way I begin to drool excessively upon hearing the words "WoodCust Style w/ Hub Program Attached".