This isn't a direct altar issue, but it does play into focus on altars to an extent. One of the things I've found to be "off" with the way games flow in treeline is the respawn timers. They are EXTREMELY short in the earlygame to the point where someone who died in an early fight could potentially rejoin the fight before it ends, and they remain very short throughout the bulk of the game, and then as players hit the 14-18 range they become incredibly long.
The reason this is a problem is in general, even if you ace the other team, until somewhere after level 9 or 10 it is essentially impossible to take map objectives (except you guessed it, the altars), and its almost never worth the risk to try to vilemaw or take a tower because the enemy team will be back up and ready to contest you (and you probably aren't in great fighting condition after winning the last fight). So the first half of the game essentially becomes win fight=take altars and shove lanes and back.
On the other side, once players get into the 14-18 range of levels, the respawn timers become HUGE for how small the map is, and an ace at this point in the game can easily be a rush through 2 towers+inhib or even a GG rush to the nexus, even if the team that got aced was ahead by quite a bit.
These things in and of themselves aren't really a problem, but when you throw it all together, the game strategy that will usually win it for you is win fights at altars and control them early, and do nothing other than that because the other objectives (towers/vilemaw) arent worth the risk, and can easily be rolled over later. Then, just farm and keep control of the altars until the opponents level to the point where they are down 30+ seconds on death, win that fight and take everything. It just feels like the strategic alternative options just arent ever worth it. Controlling the altars is always high reward low risk, and everything else is the opposite.
Sneaking vilemaw or trying to push towers down early are options, but they really aren't very good ones ever currently, and it is kind of just a game of king of the hill where one team snowballs it, then waits for respawn timers and wins easily, or it remains close, and then whoever wins a fight (still over altars) goes from no towers down to a nexus rush.
Anyway sorry for rambling, TL;DR= I think the respawn timers should be adjusted due to the size of the map (longer early-shorter late) because right now the timers limit strategic options too much.