Quote from Izraal1 >>

I’d recommend you don’t undersell yourself or your group’s capacity for adaptation. Try Castles and Crusades, try Hackmaster, try Pathfinder, Runequest, older editions of D&D.

The hobby has so much to offer. Limiting a group to just one system and then hacking it is a much poorer experience of what RPGs can offer than using systems geared towards the style you want to play in. 

 
And if "hacked D&D" is preferred over the other systems? 

You have the opinion that "hacked D&D" is a poorer experience. That's spiffy for you. It's not like that for everyone. 

If people want to play heavily homebrewed D&D - let them. You come across as if people choosing this must be missing out on other systems. Sometimes people have played other systems, and still enjoy playing the homebrewed D&D - myself being a living example. 

Please remember, people think differently than you.

I've played several RPG systems, including WhiteWolf and Cypher. Still prefer a homebrewed D&D over those. 

Quote from Izraal1 >>

I’d recommend you don’t undersell yourself or your group’s capacity for adaptation. Try Castles and Crusades, try Hackmaster, try Pathfinder, Runequest, older editions of D&D.

The hobby has so much to offer. Limiting a group to just one system and then hacking it is a much poorer experience of what RPGs can offer than using systems geared towards the style you want to play in. 

 It isn't a capacity issue. Its a time issue. 

Don’t sleep on trying 13th Age, Zweihander, or Adventurer Conquerer King before trying to house rule D&D. Each provides a different take on fantasy role playing with different emphasis. Great systems to try out in lieu of a hack. 

Sure. I will happily take recommendations. But it'll be a good while before I have any time to learn an entire system. Until that time I will just tweak things. I have had a lot of fun with this and enjoy it so far. And when I have had times I have tried other systems. BUT that is very rare as its a lot of work. Let people enjoy the games the way they want my man. If we don't have time to learn all these new things, let us do things in a way that works for us

Personally I tend to make fairly minor house rules and tweaks. To fit the tone of the game or my preference, but it's still very much recognizable as 5E. For example I'm more flexible than RAW on what can be used for a non lethal takedown. 

I can however, still imagine why people with more substantial changes might want to hack/modify D&D 5E rather than learn a new system. 

Maybe it's easier for the players to learn a modified 5E than a whole new system. Maybe it's easier to use the wealth of material for 5E with a modified system, than to try and use a system with less or trying to adapt to an entirely different system. 

Learning a new system from the ground up takes a lot of time and effort, and I can see it just being quicker and easier to modify 5E if the group already knows 5E. 

The most important rule in dnd: Have fun.

It sounds like the OP is doing just that- in the new campaign they are participating in and the more traditional game they are running.