...you don't forfeit anything if there's no door on the opposite side of the garrison, or if the opposing squad approaches from literally any angle other than the one with the door, and even then, there's no way to be closer to the same door as the enemy -- your entire argument doesn't make any sense and isn't related to the core issue of garrison hopping.
You jump out, dodge a grenade or flamer, then jump right back in, and repeat as many times as necessary.
This is becoming pointless because you are simply incapable of articulating points I am putting forward or you are point blank ignoring them.
House hopping is most effective when there are two doors, preferably with the 2nd door at the back. The back door allows you to exit and avoid any incoming threat, eg grenade, indirect fire and to a lesser extent flamers.The benefit of exiting at the rear is you do not receive any damage and the opposition cannot see what you are doing. This is the part that some people see as abusive.
If there is only one door (and the attacking side should position in front of this door) then you are correct it is harder for the attacking side to enter but it is not impossible, rather it is a matter of positioning and timing, since the delay now prevents units exiting and re-entering as quickly. The other issue with single door houses, is you will take damage when you exit since you are exposed to units in front of the house. The more units present increases the damage you take while hopping in and out. Further more single door house cannot be held anywhere near as long as two door houses because when you finally exit the chance of you squad being wiped are far greater.
The new changes do not automatically guarantee that the units exiting the house cannot re enter the house, its just not as quick as it was before and therefore less abusive. So when attacking garrisoned squads
you need to be in position to take the house when the occupants exit. This can be done with a sole squad but there are numerous variables involve. It is easier with two squads because one squad flames or nades the house while the other squad approaches the house to enter at the same time the other squad exits.
The changes are not intended to enable attacking units to just stroll up to the house and lob in a grenade and get a guaranteed return. That is never, ever, ever, going to happen so just forget it. Incase you didn't realize there is a little thing called trusight in coh2 that means certain houses have blind spots or very little warning to approaching squads. It is not competitive nor is it balanced if a garrisoned squad cannot see an opponent approaching or have sufficient time to respond.
Everything you say implies that you are viewing this issue with tunnel vision. You seem to believe that it is some tactical piece of genius on you behalf because threw a grenade at a house and if your opponent somehow evaded you, well the games broken. Every situation is different and you need to adapt and change and not expect the same tactic to work everytime.
The other thing you refuse to acknowledge is the effect that stronger explosives ( eg satchels/ gammon bombs/ bundle nades/ inffiltration nades etc) could have if house exit mechanics are increased.
Honestly if you think people are still abusing house hopping, it may well be time to consider your own tactics because it is nowhere near as effective as it used to be.