mobico, the מקור for the chiluk is from the fact that there is a chiluk in regards to שנאה:
When the Gemara describes the reason why the Beis Hamikdash was destroyed, it doesn’t just say that it was because of שנאת ישראל or שנאת אחים (like the lashon haposuk לא תשנא את אחיך), rather it emphasizes that this was שנאת חינם. See יומא ט, א.
Obviously אהבת ישראל is pretty much the same as אהבת חינם. But when using the latter term, we are EMPHASIZING that just as they hated other Jews who did nothing bad to them, so too we love other Jews even if they did nothing good for us.
This term was used by many gedolim in recent generations.
For explanation, see for example, the Lubavitcher Rebbe here:
https://www.hebrewbooks.org/pdfpager.aspx?req=15944&pgnum=338
If you don’t want to use the term, no problem. But try not to get irked.