Races in D&D are more akin to different species than they are to the concept of race used in the real world. Of course an elephant has higher constitution than a human. Have you ever felt an elephant hide? I have. Even "abstract" concepts like intelligence are easy to compare when you think of race in terms of species. Which is smarter, a human or a mouse? Having attribute differences for different species makes perfect sense in the context of roleplay and yes, I will say it is absolutely a good thing that it makes it more difficult for someone who is roleplaying a sub optimal combination compared to someone who is playing an ideal race + class combo. It reflects species realism. Poisons that would kill a human would not touch an elephant, a human would need to train their body to be resistant to them over time. In my opinion, it is not only fine that people who want to roleplay as some race + class combo which is not orthodox have to struggle a bit more as a result of it, it is actually a good thing. It reflects what it is like in the real world when someone starts from a disadvantaged position.
