A) I totally respect LDS artists who are able to maintain high standards of kindness and modesty even on the road to fame and fortune. I think others appreciate it, too. Take the Piano Guys, for instance, who are so uplifting to watch and who have close to 7 million subscribers. 7 million.
B) You don’t have to be Heifetz to inspire future generations. I can’t tell you how many students I have had who decided to study the violin because of Lindsey Stirling’s videos. Of course, when I teach my students, I encourage them to listen to many violinists as part of their music education. Names such as Hilary Hahn, Joshua Bell, Itzhak Perlman, and even Vivaldi or Paganini (though we have no recordings of the latter players) are often touted in the Shaskin studio.
C) Lindsey Stirling gave an interview once where she described a phenomenon she called "Orchestra Face" (look it up or try this link). Soon this became a standard saying in our house. Frequently after I have performed in a broadcast of Music and the Spoken Word, my husband will let me know if he saw me on the screen and whether or not I had orchestra face. Hearing Ms. Stirling talk about "Orchestra Face" is perhaps the biggest motivation I’ve found for attempting to look pleasant while I play, or, as Tabernacle Choir at Temple Square directors have put it, "sparkling" for the camera!
EDIT: After realizing the image no longer works in the link above, let me quote from the article, titled 12 Struggles Only Violinists Will Understand, what Lindsey said: “It's really hard to smile when you play.” (Aside: true, and yet she's so good at it!) “As a performer, if I ever find myself focusing it's like, oh no — orchestra face! It's not attractive at all, so I have to focus on smiling.” Yep.
Here's a short video of the two of us performing together, though I doubt she knew it at the time:
Here's a shot of her from that performance:

And here's Lindsey, showing what NOT to do: