I once read somewhere that, after some lengthy explanation, the veto doesn't even work. And I don't mean bugged, I mean that if a certain threshold was achieved (I believe it was like after a period of time and no players found) t deactivates the veto and forces you to play a more suitable game.
If that is true that's probably the reason why Relic isn't going to bother giving more vetos (since hey, it doesn't even work). It certainly won't solve the problem of not enough people playing the game, which presumably was the reason why your map veto gets vetoed (har har) in the first place.
I've no idea if that is true, but it did seem to explain why some players find themselves playing a map that they clearly vetoed. In that case, getting more vetoes wouldn't make the problem worse since you'd be even more likely to find yourself playing Steppes again because everyone else is vetoing something else.
As for new maps, they could really have just done a few easy things like Winter versions of popular maps with relatively little changes like waterways being able to sink tanks, etc. I mean they already do that with like 45% of the maps. Winter version of Ettelbruck with fewer garrison buildings and new pathways? Gameplay alone is drastically changed, and on a layout that everyone would already be familiar with.
I don't like the idea to simply implement winter version for existing summer maps as I need two vetoes in order to ban them (e.g. Semoisky winter sucks and summer aswell). The deactivation of the vetoes is IMO a good way to find games quicker. I prefer playing on a bad map in 5 minutes more than playing on a "good" map after 20 minutes of searching.
To be honest I don't veto at all as I don't like any map really that much. There are maps I enjoy a bit more, but most of the time in the loading screen I think 'well, this map again...'. Also vetoes wil reset if you switch game modes which I often do (1v1 and 2v2).