Right, but as far as I know, a house rule is actually changing or omitting a mechanical rule. I don't think saying a cleric of Heironeous wouldn't be willing to raise a follower of Nerull is a house rule, just a ruling in an area where rules are silent.
I think there definitely is a lot of tension lost when the party can regularly raise people, but the stress might come in other areas. The Cleric can raise you, but he's missing 25,000 gp (or you are) that could be spent building roads, upgrading a temple, reinforcing your castle, hiring mercenaries, etc. But, this is just a consequence other than death, which -as other have pointed out- can add to the game just as death can.
But, if you do consider that many (most?) games take place at the lower levels where raising the dead isn't the normal option in the party (nor has the funds to do so, necessarily), I think that there might be a big difference between a "you can die" style of game and a "you can't, but you can lose" style of game.
Neither are right or wrong. It's just a matter of taste. But, like I said, I do agree with the player bringing it to the GM's attention. I support the GM in staying with his preferred style, but I think it was the right call from the player to express what he likes in a game.
Yep, that's usually true. As always, play what you like